Table 1. Baseline characteristics and associations with L. interrogans PCR status among Norway rats.
| L. interrogans PCR status | |||||
| Category | Subcategory | Total (%)a | Positive (%)a | Negative (%)a | p – valuec |
| (n = 592) | (n = 66) | (n = 526) | |||
| Season | Fall | 191 (32.3) | 44 (66.7) | 147 (27.9) | <0.001 |
| Winter | 113 (19.1) | 14 (21.2) | 99 (18.8) | ||
| Spring | 209 (35.3) | 8 (12.1) | 201 (38.2) | ||
| Summer | 79 (13.3) | 0 (0) | 79 (15.0) | ||
| Sex | Male | 325 (54.9) | 39 (59.1) | 286 (54.4) | 0.64 |
| Female | 259 (43.8) | 27 (40.9) | 232 (44.1) | ||
| Sexual maturity | Mature | 328 (55.4) | 64 (97.0) | 264 (50.2) | <0.001 |
| Immature | 205 (34.6) | 1 (1.5) | 204 (38.8) | ||
| Weight (g) | Median (IQR) | 123.7 (63.6–252.8) | 302.5 (252.0–344.9) | 96.2 (59.2–221.2) | <0.001 |
| Nose-to-rump length (cm) | Median (IQR) | 16.5 (13.0–21.0) | 21.8 (21.0–23.0) | 15.5 (13.0–20.0) | <0.001 |
| Total length (cm) | Median (IQR) | 31.5 (25.2–39.0) | 40.8 (39.0–42.7) | 29.2 (25.0–37.9) | <0.001 |
| Body condition score | Median (IQR) | 2.5 (2.0–3.0) | 2.5 (2.0–3.0) | 2.5 (2.0–3.0) | 0.81 |
| Fat score (categorical) | Poor | 251 (42.4) | 2 (3.0) | 249 (47.3) | <0.001 |
| Moderate | 169 (28.5) | 18 (27.3) | 151 (28.7) | ||
| Good | 156 (26.4) | 46 (69.7) | 110 (20.9) | ||
| Fat score (continuous) | Median (IQR) | 1.0 (0.0–2.0) | 2.0 (1.0–1.67) | 1.0 (0.0–1.0) | <0.001 |
| Wound presence | No | 477 (75.5) | 29 (43.9) | 418 (79.5) | <0.001 |
| Yes | 145 (24.5) | 37 (56.1) | 108 (20.5) | ||
| Wound number | Median (IQR) | 0.0 (0.0–0.0) | 1.0 (0.0–2.0) | 0.0 (0.0–0.0) | <0.001 |
| Parous b | No | 180 (69.5) | 6 (22.2) | 174 (75.0) | <0.001 |
| Yes | 73 (28.2) | 20 (74.1) | 53 (22.8) | ||
| Pregnant b | No | 227 (87.6) | 18 (66.7) | 209 (90.1) | 0.001 |
| Yes | 26 (10.0) | 8 (29.6) | 18 (7.8) | ||
a
Frequencies and percentages may not add to 100% because of exclusion of rats with missing data for the variable in question.
b
Females only (n = 259).
c
Determined using the Chi-squared test, Fisher's exact test, or Welch's t-test, where appropriate.